U1900 on Saab
CAN Communication Bus Fault
U1900 on Saab vehicles indicates can communication bus fault. Au7o has documented this code across 1 Saab model — most commonly on 9-3. U1900 is a manufacturer-specific network code (commonly Ford) indicating a CAN communication bus fault, often a receive error. The CAN bus is the high-speed network that lets control modules such as the powertrain computer, ABS module, and instrument cluster share data. This code is set when a module stops receiving expected messages from one or more modules on the bus. Because so many systems depend on the network, a bus fault can trigger multiple warning lights and erratic behavior across systems.
Common Causes of U1900
- •Damaged, corroded, or loose CAN wiring/connectors
- •A failed or offline module pulling down the bus
- •Short to power or ground on a CAN line
- •Open circuit or broken CAN harness
- •Failed instrument cluster or ABS/PCM module
- •Low system voltage or weak battery
- •Water intrusion into a connector or module
U1900 on Saab by Model
Saab 9-3(1 issue)
- 9-3 Sunroof Drain Clog → Soaked Carpet → DICE/TWICE Module Failure2003-2011
Second-gen 9-3 (2003-2011) sunroof drains clog with debris (pollen, leaves). Water then overflows into the headliner, runs down the A-pillars, soaks the carpet, and pools in the front footwell — directly under the DICE (Driver Information Central Electronics) and TWICE modules. Wet modules can short and cause a cascade of weird electrical faults (no-start, dead instrument cluster, ABS faults, etc.).
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View U1900 across all makes →Frequently Asked Questions
What does U1900 mean on Saab?▼
U1900 stands for "CAN Communication Bus Fault." U1900 is a manufacturer-specific network code (commonly Ford) indicating a CAN communication bus fault, often a receive error. The CAN bus is the high-speed network that lets control modules such as the powertrain computer, ABS module, and instrument cluster share data. This code is set when a module stops receiving expected messages from one or more modules on the bus. Because so many systems depend on the network, a bus fault can trigger multiple warning lights and erratic behavior across systems. On Saab specifically, this code is documented across 1 model.
What causes U1900 on Saab vehicles?▼
Common causes on Saab: Damaged, corroded, or loose CAN wiring/connectors, A failed or offline module pulling down the bus, Short to power or ground on a CAN line, Open circuit or broken CAN harness, Failed instrument cluster or ABS/PCM module. Specific causes vary by model and year — see the per-model sections below.
How much does it cost to fix U1900 on a Saab?▼
Repair costs vary widely depending on the root cause and specific Saab model.
Which Saab models have U1900 documented?▼
Au7o has documented U1900 on 1 Saab model: 9-3.